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Controlling HIV-1: Non-Coding RNA Gene Therapy Approaches to a Functional Cure.

Ahlenstiel CL, Suzuki K, Marks K, Symonds GP, Kelleher AD - Front Immunol (2015)

Bottom Line: The reservoir represents a major barrier to eradication.Understanding molecular mechanisms regulating HIV-1 transcription and latency are crucial to develop alternate treatment strategies, which impact upon the reservoir and provide a path toward a "functional cure" in which there is no detectable viremia in the absence of cART.Numerous reports have suggested ncRNAs are involved in regulating viral transcription and latency.

View Article: PubMed Central - PubMed

Affiliation: The Kirby Institute, UNSW Australia , Sydney, NSW , Australia.

ABSTRACT
The current treatment strategy for HIV-1 involves prolonged and intensive combined antiretroviral therapy (cART), which successfully suppresses plasma viremia. It has transformed HIV-1 infection into a chronic disease. However, despite the success of cART, a latent form of HIV-1 infection persists as integrated provirus in resting memory CD4(+) T cells. Virus can reactivate from this reservoir upon cessation of treatment, and hence HIV requires lifelong therapy. The reservoir represents a major barrier to eradication. Understanding molecular mechanisms regulating HIV-1 transcription and latency are crucial to develop alternate treatment strategies, which impact upon the reservoir and provide a path toward a "functional cure" in which there is no detectable viremia in the absence of cART. Numerous reports have suggested ncRNAs are involved in regulating viral transcription and latency. This review will discuss the latest developments in ncRNAs, specifically short interfering (si)RNA and short hairpin (sh)RNA, targeting molecular mechanisms of HIV-1 transcription, which may represent potential future therapeutics. It will also briefly address animal models for testing potential therapeutics and current gene therapy clinical trials.

No MeSH data available.


Related in: MedlinePlus

Schematic representation of the in vivo effects of a promoter-targeted siRNA approach in a humanized mouse model and envisaged gene therapy approach. Replication-incompetent lentivirus carrying (A) the inactive control shPromA-M2 or (B) active shPromA is transduced into healthy control human CD4+ T cells. Transduced CD4+ T cells are transplanted into (NOD)/SCID/Janus kinase 3 (NOJ) knockout mice and engraftment ensues. The humanized mice are then challenged with HIV-1 and sacrificed 14 days post challenge. The shPromA antisense strand (red), associates with Ago1 (purple) and other RITS-like complex components (HDAC – yellow and EZH2 – pink) and induces heterochromatin formation with methylation marks (H3K9me2, indicated by stars) in the targeted HIV-1 promoter region. This process suppresses HIV-1 transcription and results in protection of CD4+ T cells, which results in lower pVL in mice transplanted with shPromA compared to control shPromA-M2 lentivirus-transduced PBMCs. (C) Our envisaged gene therapy approach with the future shPromA and/or sh143 TGS-inducing targets involves initial apheresis to obtain and select CD34+ HSPC and/or CD4+ T cells, which are then cultured ex vivo and transduced with the multiplexed shRNAs. The transduced cells are then infused back into the patient, whereby HIV-1 will be locked down in a latent-like state.
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Figure 1: Schematic representation of the in vivo effects of a promoter-targeted siRNA approach in a humanized mouse model and envisaged gene therapy approach. Replication-incompetent lentivirus carrying (A) the inactive control shPromA-M2 or (B) active shPromA is transduced into healthy control human CD4+ T cells. Transduced CD4+ T cells are transplanted into (NOD)/SCID/Janus kinase 3 (NOJ) knockout mice and engraftment ensues. The humanized mice are then challenged with HIV-1 and sacrificed 14 days post challenge. The shPromA antisense strand (red), associates with Ago1 (purple) and other RITS-like complex components (HDAC – yellow and EZH2 – pink) and induces heterochromatin formation with methylation marks (H3K9me2, indicated by stars) in the targeted HIV-1 promoter region. This process suppresses HIV-1 transcription and results in protection of CD4+ T cells, which results in lower pVL in mice transplanted with shPromA compared to control shPromA-M2 lentivirus-transduced PBMCs. (C) Our envisaged gene therapy approach with the future shPromA and/or sh143 TGS-inducing targets involves initial apheresis to obtain and select CD34+ HSPC and/or CD4+ T cells, which are then cultured ex vivo and transduced with the multiplexed shRNAs. The transduced cells are then infused back into the patient, whereby HIV-1 will be locked down in a latent-like state.

Mentions: Animal models for assessing HIV-1 therapeutics include various humanized murine models and non-human primates. Although the latter species contain host-restriction factors that impede HIV-1 replication and experiments performed using this model must instead use the closely related Simian immunodeficiency virus or chimeric Simian/HIV (SHIV) (76). We recently utilized a (NOD)/SCID/Janus kinase 3 (NOJ) knockout humanized mouse model to demonstrate in vivo TGS activity of shPromA, delivered via a LV (Figure 1) (73). NOJ knockout mice were reconstituted with human PBMCs transduced with the shPromA carrying lentiviral construct, which was processed into mature siPromA by cellular ribonucleases (77). HIV-1JRFL challenge of mice reconstituted with the PromA-M2 inactive control transduced PBMCs showed acute HIV-1 infection (Figure 1A) as determined by high pVL, CD4+ T cell depletion and extensive immunodeficiency (78, 79). In stark contrast, mice reconstituted with shPromA-transduced PBMCs demonstrated significantly lower pVL and normal human CD4+ to CD8+ T cell ratios in mononuclear cells recovered from the peritoneal cavity and spleen at sacrifice 14 days post HIV-1 challenge (Figure 1B) (73). This corresponds to a protective effect in the form of an induced HIV-1 “latent-like” state, which locks down active virus transcription even in this acute model of HIV-1 infection.


Controlling HIV-1: Non-Coding RNA Gene Therapy Approaches to a Functional Cure.

Ahlenstiel CL, Suzuki K, Marks K, Symonds GP, Kelleher AD - Front Immunol (2015)

Schematic representation of the in vivo effects of a promoter-targeted siRNA approach in a humanized mouse model and envisaged gene therapy approach. Replication-incompetent lentivirus carrying (A) the inactive control shPromA-M2 or (B) active shPromA is transduced into healthy control human CD4+ T cells. Transduced CD4+ T cells are transplanted into (NOD)/SCID/Janus kinase 3 (NOJ) knockout mice and engraftment ensues. The humanized mice are then challenged with HIV-1 and sacrificed 14 days post challenge. The shPromA antisense strand (red), associates with Ago1 (purple) and other RITS-like complex components (HDAC – yellow and EZH2 – pink) and induces heterochromatin formation with methylation marks (H3K9me2, indicated by stars) in the targeted HIV-1 promoter region. This process suppresses HIV-1 transcription and results in protection of CD4+ T cells, which results in lower pVL in mice transplanted with shPromA compared to control shPromA-M2 lentivirus-transduced PBMCs. (C) Our envisaged gene therapy approach with the future shPromA and/or sh143 TGS-inducing targets involves initial apheresis to obtain and select CD34+ HSPC and/or CD4+ T cells, which are then cultured ex vivo and transduced with the multiplexed shRNAs. The transduced cells are then infused back into the patient, whereby HIV-1 will be locked down in a latent-like state.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4584958&req=5

Figure 1: Schematic representation of the in vivo effects of a promoter-targeted siRNA approach in a humanized mouse model and envisaged gene therapy approach. Replication-incompetent lentivirus carrying (A) the inactive control shPromA-M2 or (B) active shPromA is transduced into healthy control human CD4+ T cells. Transduced CD4+ T cells are transplanted into (NOD)/SCID/Janus kinase 3 (NOJ) knockout mice and engraftment ensues. The humanized mice are then challenged with HIV-1 and sacrificed 14 days post challenge. The shPromA antisense strand (red), associates with Ago1 (purple) and other RITS-like complex components (HDAC – yellow and EZH2 – pink) and induces heterochromatin formation with methylation marks (H3K9me2, indicated by stars) in the targeted HIV-1 promoter region. This process suppresses HIV-1 transcription and results in protection of CD4+ T cells, which results in lower pVL in mice transplanted with shPromA compared to control shPromA-M2 lentivirus-transduced PBMCs. (C) Our envisaged gene therapy approach with the future shPromA and/or sh143 TGS-inducing targets involves initial apheresis to obtain and select CD34+ HSPC and/or CD4+ T cells, which are then cultured ex vivo and transduced with the multiplexed shRNAs. The transduced cells are then infused back into the patient, whereby HIV-1 will be locked down in a latent-like state.
Mentions: Animal models for assessing HIV-1 therapeutics include various humanized murine models and non-human primates. Although the latter species contain host-restriction factors that impede HIV-1 replication and experiments performed using this model must instead use the closely related Simian immunodeficiency virus or chimeric Simian/HIV (SHIV) (76). We recently utilized a (NOD)/SCID/Janus kinase 3 (NOJ) knockout humanized mouse model to demonstrate in vivo TGS activity of shPromA, delivered via a LV (Figure 1) (73). NOJ knockout mice were reconstituted with human PBMCs transduced with the shPromA carrying lentiviral construct, which was processed into mature siPromA by cellular ribonucleases (77). HIV-1JRFL challenge of mice reconstituted with the PromA-M2 inactive control transduced PBMCs showed acute HIV-1 infection (Figure 1A) as determined by high pVL, CD4+ T cell depletion and extensive immunodeficiency (78, 79). In stark contrast, mice reconstituted with shPromA-transduced PBMCs demonstrated significantly lower pVL and normal human CD4+ to CD8+ T cell ratios in mononuclear cells recovered from the peritoneal cavity and spleen at sacrifice 14 days post HIV-1 challenge (Figure 1B) (73). This corresponds to a protective effect in the form of an induced HIV-1 “latent-like” state, which locks down active virus transcription even in this acute model of HIV-1 infection.

Bottom Line: The reservoir represents a major barrier to eradication.Understanding molecular mechanisms regulating HIV-1 transcription and latency are crucial to develop alternate treatment strategies, which impact upon the reservoir and provide a path toward a "functional cure" in which there is no detectable viremia in the absence of cART.Numerous reports have suggested ncRNAs are involved in regulating viral transcription and latency.

View Article: PubMed Central - PubMed

Affiliation: The Kirby Institute, UNSW Australia , Sydney, NSW , Australia.

ABSTRACT
The current treatment strategy for HIV-1 involves prolonged and intensive combined antiretroviral therapy (cART), which successfully suppresses plasma viremia. It has transformed HIV-1 infection into a chronic disease. However, despite the success of cART, a latent form of HIV-1 infection persists as integrated provirus in resting memory CD4(+) T cells. Virus can reactivate from this reservoir upon cessation of treatment, and hence HIV requires lifelong therapy. The reservoir represents a major barrier to eradication. Understanding molecular mechanisms regulating HIV-1 transcription and latency are crucial to develop alternate treatment strategies, which impact upon the reservoir and provide a path toward a "functional cure" in which there is no detectable viremia in the absence of cART. Numerous reports have suggested ncRNAs are involved in regulating viral transcription and latency. This review will discuss the latest developments in ncRNAs, specifically short interfering (si)RNA and short hairpin (sh)RNA, targeting molecular mechanisms of HIV-1 transcription, which may represent potential future therapeutics. It will also briefly address animal models for testing potential therapeutics and current gene therapy clinical trials.

No MeSH data available.


Related in: MedlinePlus